Hiero II of Syracuse

Hiero II of Syracuse (308 BC-215 BC) was the tyrant of Syracuse from 270 to 215 BC, succeeding Pyrrhus of Epirus and preceding Hieronymus of Syracuse.

Biography
Hiero was the illegitimate son of the Syracusian noble Hierocles, and he served as a general of Pyrrhus of Epirus. When Pyrrhus left Sicily in 275 BC, the army and citizens of Syracuse appointed Hiero the commander of the Epirote troops, and he was proclaimed king after defeating an army of marauding mercenaries near Mylae on the Longanus River. In 264 BC, the mercenaries allied with the Roman Republic during the First Punic War, and Hiero was forced back to Syracuse by the Romans shortly after joining forces with the army of Carthage. From 263 to 215 BC, he was loyal to the Romans, and he employed Archimedes to build up the defenses of his city; he also had Archimedes check if his crown had been made properly; Archimedes measured the density of the crown and discovered the principle of displacement, causing him to famously cry "Eureka" while running around the streets of Syracuse naked. He died in 215 BC at the age of 93.